Lubricant pump



0V. 4, 1952 A, P, FOX ETAL I 2,616,524

LUBRICANT PUMP Filed April 22, 1950 4 Sheets-Sheet l MY H f. 7 9 l Il 7 l Q 1 .g l L l a 31 5 3 .al V 3 95 97 :.9 37 7395 79 97 33 71 7 33 j 39 a? 45 59 7g3 2e 735? 7g Z6 56 38 "ga 47g i i 7 55 59 44/59 '55 4 4959 5, m a -P foy,

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LUBRICANT PUMP 4 Sheets-Sheet 3 v I"\ vwl/Mu@- FIG. 9.

Filed April 22, 1950 Fl. IO.

A. RFQ): E11-M.

LUBRICANT PUMP 4 Sheets-Sheet 4 FI C) l i 239 f f77 245 ,79

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Patented Nov. 4, 1952 LUBRICAN T PUMP Alexander P. Fox, University City, and Lutwin C. Rutter, Maplewood, Mo., assgnors to Lincoln Engineering Company, St. Louis, M0., a corporation of Missouri Application April 22, 1950, Serial No. 157,561

This invention relates to lubricant pumps and, more particularly, to hand-operated pumps of this class for use in a lubrication system to supply lubricant Lto lubricant injectors.

The invention particularly pertains to handoperated lubricating pumps for supplying lubricant through a supply line to a plurality of lubricant injectors of the type which act to inject a measured charge of lubricant into a bearing or other item to be lubricated upon development of injector-cycling pressure in the supply line, and which require venting of the supply line to reset and refill with lubricant from the supply line. Such injectors are shown, for example, in U. S. Patents 2,122,177, 2,141,022, 2,283,638 and 2,448,583. The object of the invention is the provision of an improved hand-operated pump for the purpose described which, with a simplified, compact and economical construction, provides positively and completely for venting of the lubricant line throughout the duration of periods of non-operation of the pump, whatever these periods may be, which assures that no venting of the supply line can occur during pumping, and which can supply as many injectors as desired, within certain practical limits, without being of particularly large size and without being difcult to operate.

In general, a pump of this invention comprises a pump cylinder having an inlet in communication with a lubricant supply, and an outlet. A plunger is reciprocable in the cylinder across the inlet from a retracted position through pressure and return strokes to pump lubricant from the supply and force it through the outlet. In the outlet is a check valve which is adapted to open during pressure strokes and to close during return strokes of the plunger. The check valve is provided with a vent, for venting the pump outlet to the cylinder and hence to the supply. Associated with the vent is a vent valve, which is controlled by the plunger in such manner as to vent the outlet to the cylinder only when the plunger is in retracted position and otherwise to maintain the vent closed. Other features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplied in the structures hereinafter described, and the scope f the application of which will be indicated in the following claims.

In the accompanying drawings, in which several of various possible embodiments of the invention are illustrated,

20 Claims. (Cl. 184-28) Fig. 1 is a full central vertical section of a pump of this invention, illustrating the pump plunger thereof in fully retracted position;

Fig. 2 is a partial elevation, with parts broken away and shown in section on the same plane as Fig. l, illustrating a moved position of parts;

Fig. 3 is an elevation of Fig. l as viewed from the right, with parts broken away and shown in section on line 3;-3 of Fig. 1;

Fig. 4 is an elevation like Fig, 2, with parts broken away and shown in section, illustrating parts in the position occupied at the end of a pressure stroke of the pump plunger;

Fig. 5 is a horizontal section taken on line 5-5 of Fig. 4;

Fig. 6 is a full central vertical section of another pump of this invention, taken on line 6--6 of Fig. 10, illustrating the pump plunger thereof in fully retracted position;

Fig. 7 is an enlarged fragment of Fig. 6;

Fig. 8 is a View like Fig. 7 illustrating a moved position of parts;

Fig. 9 is a View like Figs. 7 and 8 illustrating a l further moved position of parts;

' Fig. 10 is a plan View of Fig. 6;

Fig. ll is a vertical section taken on line l t-l l of Fig. l0; and,

Fig. 12 is a vertical section taken on line |2I 2 of Fig. 6.

Similar reference characters indicate corresponding parts throughout the several views of the drawings.

Referring to the drawings, Figs. l-5 illustrate a pump of this invention which is particularly suitable for pumping oil through a supply line to a plurality of injectors of the type above described. As shown, this pump comprises a lubricant container, generally designated l, comprising a barrel 3 having a tapered lower end 5. Threaded on the upper end of the barrel is a head 1 formed for bracketing the pump in vertical position on or adjacent an apparatus equipped with injectors for lubricating various elements of the apparatus requiring lubrication, such as bearings. The head 1 is formed with a vertical guide bearing 9 for a p-iston rod Il adapted to reciprocate vertically in the line of the axis of the barrel. The upper end of the rod above the head 1 is formed flat, as indicated at I3, and is pin-connected at I5 in a clevis l1 at the upper end of a curved operating lever or handle I9. A link 2l is pin-connected at one end to the handle in the clevis, as indicated at 23, and at its other end to the head l, as indicated at 25, to constrain the handle to swing in a vertical plane. The handle is curved to extend down alongside the container I. By grasping the lower end of the handle and swinging it upward, the rod II may be driven downward. Engagement of the part of the handle grasped by the hand with the wall of the barrel 3 at about the upper end of the taper determines a raised, retracted position of the rod, illustrated in Fig. 1. The handle has a knob 26 at its lower end. The arrangement is such that when the handle is grasped at its lower end in the normal way to reciprocate the rod it is impossible to swing the handle into engagement with the barrel because the fingers come between thehandle and the barrel. The head 1 is formed with a lling opening 21, closed by a spring cap 28.

The piston rod in moving downward, eiects a pressure stroke of a piston or plunger 29 which reciprocates in a bushing 3| constituting a pump cylinder located in the lower end of the barrel 3. The cylinder 3| is formed adjacent its lower end with a head 33 which is threaded into the lower end of the barrel. Above the head, the cylinder is provided with radial inlet ports 35, surrounded by a strainer 31, for ow of lubricant from the container into the cylinder 3| when the lower end of the plunger 29 is raised above the ports. The cylinder 3| is open at both ends and its lower end is counterbored to provide an enlarged axial outlet opening 38 with an outwardly facing annular valve seat 39 at the inner end of the opening for seating a special valve member 4|.

The valve member 4| comprises a hollow cylindrical body 43 formed with a nose 45 at its upper end for sealing engagement with the valve seat 39. The body 43 is formed below the nose with two axially spaced heads, the upper head being designated 41 and the lower head being designated 49, which guide is for vertical sliding movement toward and away from the valve seat 39 in a vertical cylindrical valve passage 5| formed in a pump outlet body 53. The latter is of generally hollow cylindrical form in its upper portion and has an outwardly extending flange 55 at its upper end. It is held in assembly as an extension from the lower end of the pump cylinder 3| by a gland nut 56 which compresses a packing 51 between the ange 55 and the lower end of the pump cylinder. rlhe upper head 41 on the valve 4| is hexagonal or the like to provide spaces 58 (Fig. 5) for flow of lubricant from above the nose 45 to the space between the heads 41 and 49, and the cylindrical body 43 is provided with radial ports 59 between the heads for flow of lubricant from the space between the heads 41 and 49 into the outlet passage 5| below the nose. The valve 4| is biased upward toward sealing engagement of its nose with the valve seat 39 by a spring 6| reacting from the lower end of the passage 5|. The passage 5| opens at its lower end into a smaller vertical axial passage 63 in the body 53. The body 53 is formed with a transverse port 95 leading from passage 63 which constitutes the pump outlet and into which may be connected a supply line (not shown) leading to the injectors.

A short tube 61 is threaded in an aperture through the nose 45 of the valve 4|, the bore of the tube providing a passage or vent 69 allowing for communication from below the nose to the pump cylinder 3|. The upper end of the tube constitutes a valve seat for a needlevalve 1|. The tube extends below the nose and a packing 13 is compressed by thev spring 6| betweenthe nose and a washer 15. The plunger 29 is of hollow cylindrical form and, at its lower end or pressure face, has an inwardly turned annular flange or shoulder 11 defining a central opening 19. The upper end of the needle valve has a close sliding t in this opening. The lower end of the needle valve is tapered to seat in the upper end of the tube 61. The needle valve has a reduced-diameter extension or stem 8| extending axially upward from its upper end within the plunger 29. Threaded on the upper end of the plunger is a head 83 which has an outwardly directed flange 85 forming a spring abutment shoulder andan upwardly extending stud 81 which ts loosely in an opening 89 in the lower end of the piston rod The plunger 29 is biased upward by a helical compression spring 9| surrounding the pump cylinder 3| and plunger 29 and reacting from the head 33 against the shoulder 85. A helical compression spring 93 located within the plunger is compressed between the head 83 and a collar 95 loosely slidable on the stem 8| within the plunger, the spring surrounding the stem.

The parts are so proportioned that when the handle |9 is in engagement with the barrel 3, and piston rod is raised to the upper end of its stroke, as illustrated in Fig. 1, the spring 9| holds the plunger 29 in a fully retracted position at the upper limit of its stroke wherein its lower end is raised to unblock the ports 35. Under these circumstances oil flows from the supply in barrel 3 through the ports 35 into the pump cylinder 3| and fills the latter below the plunger and above the check valve 4|. Also, the collar is lifted at this time by the annular ange 11 at the lower end of the plunger above the shoulder 91 at the lower end of the valve stem 8|, thereby relieving the needle valve 1| of the force of spring 93. Thus, with the parts in the position shown in Fig. l, spring 93 does not exert its force on the needle valve at all, and the latter may move freely upward a small distance until its shoulder 91 engages the collar 95. Movement of the needle valve through this small distance is sufficient to unblock the vent 69. When the handle is grasped by the hand at its lower end in normal manner, the rod is moved downward and moves the plunger 29 downward from its retracted position a distance such that the collar 95 engages the shoulder 91, whereupon spring 93 exerts its force on the needle Valve 1| to bias it downward and thereby block the vent 69. Closing of the vent 69 occurs in an intermediate position of the plunger prior to closing of the cylinder inlet ports 35. As the handle is swung upward, the spring 93ismore heavily compressed and thus exerts increased force on the needle valve to hold it in closed position.

The pump is equipped with an indicator to afford a visible indication that suiicient pressure has been developed in the system supplied by the pump to cycle the injectors. As shown best in Fig. 3, this indicator comprises a fitting |0| threaded in a transverse socket |03 in the lower end of the body 53. The inner end of the fitting is smaller than the socket so that a pressure chamber |95 is provided at the inner end of the socket. The fitting has a bore |91 in its inner end open to the chamber |05 and its outer endv is counterbored as indicated at |09. A plunger is slidable in the bore, with a packing 3 at its inner end. A stem H5 having a head ||1 at its inner end is slidable in the counterbore |09, the outer end of the' stem extending through a plug ||9 threaded in the outer end of the counterbore. A compression spring |2| is located in the counterbore surrounding the stem and reacts from the plug against the head ||1 to bias the stem to an innermost position wherein the head engages the shoulder |23 at the inner end of the counterbore. In this position, the outer end of the stem just protrudes from the plug. A narrow passage |25 in the body 53 connects the pump outlet passage 5| and the chamber |05. The arrangement is such that when the pressure in the pump outlet and chamber |05 reaches a predetermined injector-cycling value, the plunger is driven to the left as viewed in Fig. 3 and drives the stem ||5 to the outer position indicated in dotted lines in Fig. 3, to provide a visible indication that injector-cycling pressure has been attained. Upon relief of pressure, spring |2| biases the stem and plunger back to their initial position.

The above-described pump is mounted in vertical position on or adjacent apparatus equipped with lubricant injectors of the type above mentioneol, with an injector supplyr line (not shown) connecting the pump outlet port 05 and the injectors. The container I is filled with oil through filling opening 21. Spring 9| normally holds the plunger 29 and the rod in raised position at the upper limit o their stroke, with the lower end portion of the handle |9 engaging the wall of the container. With the plunger in retracted position at the upper limit of its stroke, the collar 95 is lifted by the flange 11 above the shoulder 91, and the valve 1| is entirely relieved of the force of the spring 93. Thus, if there is any pressure in the pump outlet below the valve 4|, this will open the needle valve and be vented upward through the vent 59 into the pump cylinder.

To cycle the injectors so that each will deliver a charge of oil, the handle is grasped and pumped up and down until the pressure developed by the pump in the injector supply line reaches injectorcycling value (600 to 1000 p. s. i.. for example), as indicated by popping out of the indicator stem ||5, which acts as a telltale. Each upstroke of the handle causes a downward pressure stroke of the pump plunger 29 and, upon each downstroke of the handle, spring 9| returns the plunger 29 through a return stroke, at the end of which the pump cylinder 3| is charged for the next pressure stroke. Immediately upon grasping the handle, the plunger is moved down a distance such that the force of spring 93 is brought to bear upon the needle valve 1|, so that this valve closes (see Fig. 2). Upon each pressure stroke of the plunger, the force of the spring 93 on the needle valve decreases from the initial to the nal end of the pressure stroke. Though the plunger 29 moves upward upon each return stroke, it cannot move upward far enough to relieve the force of spring 93 on the needle valve, because as long as the handle is being grasped, it is impossible for the handle to be moved into engagement with the container, and hence it is impossible for the plunger 29 to move upward far enough for its flange 11 to lift the collar 95. Thus, needle valve 1| remains closed throughout the operation of handle |9 to hold pressure in the pump outlet and the supply line. it will be understood that upon each downstroke of the plunger 29, the check valve 4| opens for flow of oil from the cylinder to the pump outlet.

A* Assoon as the operator is apprised of the development of injector-cycling pressure in the pump outlet bythe popping outof the telltale ||5, he simply releases the handle |9. Spring 9| thereupon biases the plunger 29 and the rod upward to the upper limit of their stroke, the handle |9 returning to its rest position in engagement with the container (Fig. l). This frees the needle valve 1| of the force of spring 93, and the valve 1| opens under the pressure in the passage 5| and vents the injector supply line, oil returning to the container Upon venting of the supply line, the injectors recharge, as will be understood. The valve 1| remains free to open as long as the handle is at rest, to insure venting of the injector supply line.

From the above, it will be seen that the valve 4| acts as a check valve in the pump outlet adapted to open during pressure strokes and to close during return strokes of the pump plunger 29. The needle valve 1| acts as a vent valve in association with the vent B9 in the check valve 4|. The needle or vent valve 1| is mechanically controlled by the plunger in such manner as positively to close the vent E9 when the plunger, in being moved from its Fig. l retracted position. reaches an intermediate position prior to closing of the cylinder inlet ports 35, and positively to maintain the vent closed throughout the remainder of a pressure stroke and also during retraction of the plunger provided the plunger is not retracted past said intermediate position. Thus the valve 1| is controlled to vent the pump outlet to the pump cylinder 3| only when the plunger is in retracted position (Fig. l) and otherwise closes the vent.

Figs. 6-12 illustrate a modified type of pump of this invention which is particularly suitable for pumping grease, as distinguished from oil, through a supply line to a plurality of injectors. As shown, this pump comprises a lubricant container, generally designated |3|, comprising a container cylinder |33 having an upper head |35 and a lower head |31. The upper head is removably threaded on the upper end of the barrel. At |39 is shown a rod extending through the center of the head and slidable in a guide bearing |4| carried by the head. On the upper end of the rod above the head |35 is a knob |43. A piston |45 is slidable on the rod within the cylinder |33. The piston is biased downward toward the head |31 by a helical compression spring |41 in the cylinder surrounding the rod and reacting from the head |35. The arrangement is such that the head |35, rod |39, piston |45 and spring |41 may be removed from the cylinder as a unit, the cylinder filled with grease, and the head |35 and associated parts replaced, whereupon the expansion of the spring forces the grease toward and into the lower head |31. The cylinder may be loaded by pumping grease into it through a suitable port, if desired. At |49 is shown a telltale slidable in the upper head |35 for indicating when the cylinder is illed if loaded in this manner.

The lower head |31 is formed for bracketing the pump in vertical position on or adjacent an apparatus equipped with injectors for lubricating various elements of the apparatus requiring lubrication, such as bearings. It has a transverse stepped cylindrical opening |5|, which extends through the head from one side to the other. Fixed in this passage as by threading at |53 is a bushing |55 constituting a pump cylinder. Packing for the cylinder |55 is shown at |51. |59 and IBI. The cylinder is formed with an annular peripheral groove |63 adjacent one end of the opening this groove providing an annular chamber receiving grease from the container |3| through a passage |64 in the head. Grease may now from this chamber into the cylinder through radial ports |65 in the wallof the cylinder.

A pump plunger |61 is reciprocable in the pump cylinder across the inlets |65 from the fully retracted position illustrated in Fig. 6 through pressure and return strokes. The plunger extends out of one end (the right end as viewed in Fig. 6) of the cylinder and its outer end is formed as a flat in a vertical plane, as indicated at |69, being pin-connected at |1| in a clevis |13 at'the lower end of an operating lever or handle |15. .A link |11 is pin-connected at one end to the handle in the clevis, as indicated at |19, and at its other end to the head |31, as indicated at |8I, to constrain the handle to swing in a vertical plane, eiecting a pressure stroke of the plunger when swung down, and a return stroke of the plunger when swung up. The handle extends upward alongside the container and its upward swing is limited by engagement of its upper end with the container |3I. This engagement of the upper end of the handle with the container determines the fully retracted position of the plunger |61. When the upper end of the handle is grasped. it is of necessity moved away from the container, and it is impossible to swing the upper end of the handle into engagement with the container when grasped because the iingers come between the handle and the container. A tension spring |83 may be connected between the handle and the head |31 to keep the handle from rattling against the container if the pump is mounted where it is subjected to vibration.

The other end of the pump cylinder |55 (its left end as viewed in Fig. 6) is counterbored to provide an enlarged axial outlet opening or chamber |85 atV the inner end of which is an annular shoulder |81 forming an annular outwardly facing valve seat. A cheek valve |89 located in chamber |85 is biased toward the valve seat |81k by a spring |9| reacting from a plug |93 threaded in the left end of the cylinder |55. The cylinder |55 is formed with an annular peripheral rroove |95v around the chamber |85, communication between the chamber and the groove being provided by radial ports |91 in the wall of the cylinder |55. The groove is located between packings |59 and |E|. At |99 is shown the pump outlet pcrt, which is in communication with the groove and into which an injector supply line .nay be connected The check valve |89 comprises a hollow cylindrical body 29| formed with a nose 29S at its right end for sealing engagement with the valve seat |81. The body is formed with a hexagonal head 295 or the like, which guides it for sliding movement in the chamber |85. In the nose 293 is an axial vent opening 291. An annular packing member or washer 299 having its central opening aligned with the vent opening 201 is compressed against the hack of the nose within the body 28| by a gland nut 2 threaded in the body from its open left end. The opening 261' in the nose, the opening in the packing member2=39 and the opening in the gland nut 2| constitute a vent port, designated 2|3.

Extending through the pump cylinder |55 from the inner end of the plunger |61 is a vent valve 2 l5. This consists of a rod of such diameter as to be capable of a sliding sealing t in the vent port 2|3 having a reduced-diameter end extension 2| 1. The length of the valve 2|5 is such that when the plunger 51 is in its fully retracted position (Figs. 6 and 7 the valve is withdrawn from the vent port 2|3. Under these circumstances, the vent valve extension 2|1 extends through the vent port, but the chamber is in communication with the portion of the pump cylinder |55 to the right of the check valve |89 through the vent port around the extension. When the handle |15 is grasped, the plunger |61 moves from its retracted position to the left a distance such that valve 2|5 enters and blocks the vent port (Fig, 8). Closing of the vent 2|3 occurs in an intermediate position of the plunger prior to closing of the cylinder inlet ports |65. The vent valve then maintains the vent port blocked throughout the remainder of a pressure stroke of the plunger and also maintains the vent port blocked as the plunger returns toward retracted position until it reaches its fully retracted position (Fig. 1). However, as long as the handle is being grasped, the plunger cannot be returned all the way to fully retracted position and hence under these circumstances, the vent valve keeps the vent port blocked. When the plunger |51 is moved through a pressure stroke, the extension moves through the spring |9| and enters a bore 2|9 in the plug |93.

The pump of Figs. 6-12, like that of Figs. l-5, is equipped with an indicator to afford a visible indication that sufficient pressure has been developed in the system supplied by the pump to cycle the injectors. As shown best in Fig. ll, this indicator comprises a fitting 22| threaded in a vertical socket 223 in the head |31. The fitting has a bore 224 through its inner end and its outer end is counterbored as indicated at 225. The bore 224 is in line with a vertical bore 221 in the head |31 below the socket 223. A bore 229 (Figs. l1 and l2) in the head connects the pump outlet groove and the lower end of the bore 221. The outer end of the bore 229 is plugged as indicated at 23| (Fig. l2).

A plunger 233 is slidable in the bores 224 and 221 and through a packing 235 compressed between the inner end of the tting 22| and the inner end of the socket 223. A stem 231 having a head 239 at its inner end is slidable in the counterbore 225, the outer end of the stem extending through a plug 26| threaded in the outer end of the counterbore. A compression spring 243 is located in the counterbore surrounding the stem and reacts from the plug against the head 239 to bias the stem to an innermost position wherein the head engages the shoulder 245 at the inner end of the counterbore. In this position, the outer end of the stem just pretrudes from the plug. The arrangement is such that when the pressure in the pump outlet reaches a predetermined injector-cycling value, the plunger 233 is driven upward as viewed in Fig. ll and drives the stem 231 to the outer position indicated in dotted lines in Fig, l1, to provide a visible indication that injector-cycling pressure has been attained. Upon relief of pressure, spring 253 biases the stem and plunger back to their initial position.

The pump or" Figs. 6-12 is mounted in vertical position on or adjacent apparatus equipped with lubricant injectors of the type above mentioned, with an injector supply line (not shown) connecting the pump outlet port |99 and the injectors. The container 3| is lled ybelow the piston with grease, which is forced by the piston toward and into the annular pump inlet chamber |63. The handle and the plunger |61 normally occupy the fully retracted position shown in Fig. 6, with the upper end of the handle engaging the container and the plunger retracted to clear the inlet ports |65, so that grease may flow into the pump cylinder. In the fully retracted position of the plunger, the vent valve 2 l5 is withdrawn from the vent port 2 I3 (Fig. '7) so that the pump outlet port |99 is in communication back to the container |3| through groove |95, ports |91, chamber |85, vent port 2|3, the pump cylinder |55, ports |65, chamber |63 and passage |64, thereby to vent the injector supply line.

To cycle the injectors so that each will deliver a charge of grease, the handle |15 is grasped and pumped up and down until the pressure developed by the pump in the injector supply line reaches injector-cycling value, as indicated by the popping out of the telltale indicator stem 231. Each downstroke of the handle causes a pressure stroke of the pump plunger |61 and each upstroke of the handle returns the plunger toward, but not all the Way to its fully retracted position of Figs, 6 and '7. Immediately upon grasping the handle, the plunger of necessity is moved far enough to move the vent valve 2 5 to closed position blocking the vent port 2|3 (Fig. 8). While pumping, the vent valve does not open, because as long as the handle is grasped it is impossible to retract the plunger far enough to move the vent valve to open position. Thus, the vent port 2 I3 remains closed throughout the operation of the pump handle. It will be understood that upon each pressure stroke of the plunger, the check valve |89 opens (Fig. 9) for ow of grease from the pump cylinder to the pump outlet.

As soon as the operator is apprised of the development of injector-cycling pressure in the pump outlet by the popping out of the telltale 231, he simply releases the h-andle |15. The pressure in the pump outlet chamber |85, acting on the end of vent valve extension 2|1, thereupon drives the vent valve 2|5 and the plunger |61 to their fully retracted position of Figs. 6 and '1, whereupon the pump outlet (and the injector supply line) is vented back to the container |3|. It will be understood that the pressure developed by the spring |41 is considerably less than the pressure developed in the pump outlet and the injector supply line. This returns the handle |15 to its fully retracted position determined by engagement of its hand-grasp portion with the container. While the spring |63 assists in this return, the primary purpose of this spring is toprevent rattling, and it could be omitted. Upon venting of the supply line, the injectors re-charge, as will be understood. The vent valve 2 5 remains open as long as the handle is at rest, to insure venting of the injectorsupply line.

From the above, it will be seen that the valve |89 acts as la check valve in the pump outlet adapted to open during pressure strokes and to close during return strokes of the pump plunger |61. ciation with the vent 2 I3 in the check valve |89, and is mechanically controlled bythe plunger in such manner as positively to close the vent 2|3 when the plunger, in being moved from its Fig. 6 and Fig. 7 retracted position, reaches an intermediate position prior to closing of the cylinder inlet ports |65, and positively to maintain the vent closed throughout the remainder of a pressure stroke and also during retraction of the .plunger provided the plunger is not retracted past The valve 2|5 acts as a vent valve in assol0 said intermediate position. Thus the valve 2|5 is controlled to vent the pump outlet to the pump cylinder |55 only when the plunger is in fully retracted position (Figs. 6 and '1) and otherwise keeps the vent closed.

It will be seen that as to both the Fig, l and Fig. 6 pumps, whenever the pump is not being operated, the pump handle occupies its position of rest in engagement with the lubricant container of the pump, which serves as a stop for the handle. With the handle in rest position, the pump outlet is vented back to the container through the pump cylinder, thus providing positively and completely for venting the lubricant line supplied by the pump throughout the duration of periods of non-operation of the pump, whatever these periods may be. As soon as the operator grasps the handle, however, the vent is closed, to hold pressure in the lubricant line. During pumping, the vent cannot be opened because the handle cannot be returned to its rest position as long as it is being grasped by the hand. The pump may be stroked as many times as necessary to build up injector-cycling pressure in the pump outlet and lubricant line. Thus, a large number of injectors may be serviced by one pump, which need not be of particularly large size nor diiicult manually to operate.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained. Y

As many changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim:

1. A lubricant pump comprising a pump cylinder having an inlet and an outlet, a plunger reciprocable in the cylinder and movable across the inlet from a retracted position through a pressure stroke and back to retr-acted position through a return stroke, a check valve in the outlet adapted to open during pressure strokes and to close during return strokes of the plunger, said check valve having a vent therein, and a vent valve in association with the vent in the check valve mechanically controlled by the plunger to vent the pump outlet to the cylinder when the plunger is in retracted position and positively to close the vent when the plunger, in being moved from its retracted position, reaches an intermediate position prior to closing of the cylinder inlet, the vent valve maintaining the vent positively closed throughout the remainder of a pressure stroke and also during retraction of the plunger provided the plunger is not retracted past said intermediate position A 2. A lubricant pump comprising a pump cylinder having an inlet and an outlet, a plunger reciprocable in the cylinder, a handle connected to the plunger for manually moving it across the inlet from a retracted position through a pressure stroke, the retracted position of the plunger being determined by engagement of the handle with a stop, the stop being engaged by the part of the handle grasped by the hand so that in grasping the handle it is necessarily moved awai7 from the stop, and so that while the handle is grasped it cannot be moved against the stop, a check valve in the outlet adapted to open during pressure strokes and to close during return strokes of the plunger, said check valve having a vent therein, and a vent valve in association 11 with the vent mechanically controlled by the plunger to vent the pump outlet to the cylinder when the plunger is in retracted position and positively to close the vent when the plunger, in being moved from its retracted position, .reaches an intermediate position prior to closing of the cylinder inlet, the vent valve maintaining the Vent positively closed throughout the remainder of a pressure stroke and also during retraction of the plunger provided the plunger is not retracted past said intermediate position.

3. A lubricant pump comprising a lubricant container, a pump cylinder associated with the container having an inlet in communication with the container and an outlet, a plunger reciprocable in the cylinder, a handle mounted for swinging movement toward and away from the container connected to the plunger for manually moving it across the inlet from a retracted position through a pressure stroke when the handle is swung away from the container, the retracted position of the plunger being determined by engagement of the handle with the container, the container being engaged by the part of the handle grasped by the hand so that in grasping the handle it is necessarily moved away from the container, and so that while the handle is grasped it cannot be moved into engagement with the container, a check valve in the outlet adapted to open during pressure strokes and to close during return strokes of the plunger, said check valve having a vent therein, and a vent valve in association with the vent mechanically controlled by the plunger to vent the pump outlet to the cylinder and through the cylinder inlet to the container when the plunger is in retracted position and positively to close the vent when the plunger, in being moved from its retracted position, reaches an intermediate positionA prior to closing or" the cylinder inlet, the vent valve maintaining the vent positively closed throughout the remainder of a pressure stroke and also during retraction of the plunger provided the plunger is not retracted past said intermediate position.

4. A lubricant pump as set forth in claim 1, further comprising a pressure indicator associated with the pump cylinder having a port in communication with the pump outlet and adapted to indicate development of a predetermined pressure by the pump.

5. A lubricant pump as set forth in claim 2, further comprising a pressure indicator associated with the pump cylinder comprising a telltale biased in one direction to a retracted position by a spring and in the opposite direction by pressure in the pump outlet and adapted to move away from retracted position against the spring bias when the pressure in the pump outlet reaches a predetermined value.

6. A lubricant pump as set forth in claim 3, further comprising a pressure indicator associated with the pump cylinder comprising a stern axially movable in a chamber and spring-biased in one direction to a retracted position in the chamber, said stem being biased in the opposite direction by the pressure in the pump outlet and adapted to move away from its retracted position against its spring bias to a position protruding from the chamber when the pressure in the pump outlet exceeds a predetermined value.

7. A lubricant pump comprising a pump cylinder having a radial inlet and an enlarged axial outlet opening at one end providing an annular outwardly facing valve seat at the inner end of the opening, a plunger reciprocable in the cylinder and movable across the inlet from a retracted position toward the outlet opening through a pressure stroke and back to retracted position through a return stroke, a check Valve in the outlet opening, a spring biasing the check valve toward the valve seat, the check valve having an axial vent therethrough, and a vent vale working in the pump cylinder in association with the vent controlled by the plunger mechanically to vent the outlet opening to the cylinder when the plunger is in retracted position and positively to close the vent when the plunger, in being moved from its retracted positon, reaches an intermediate position prior to closing of the cylinder inlet, the Vent valve maintaining the vent positively closed throughout the remainder of a pressure stroke and also during retraction of the plunger provided the plunger is not retracted past said intermediate position.

8. A lubricant pump comprising a pump cylinder having a radial inlet and an enlarged axial outlet opening at one end providing an annular outwardly facing valve seat at the inner end of the opening, a plunger reciprocable in the cylinder, a handle connected to the plunger for manually moving it across the inlet from a retracted position toward the outlet opening through a pressure stroke, the retracted position of the plunger being determined by engagement of the handle with a stop, the stop being engaged by the part of the handle grasped by the hand so that in grasping the handle it is necessarily moved away from the stop, and so that while the handle is grasped it cannot be moved against the stop, a check valve in the outlet opening, a spring biasing the check valve toward the valve seat, the check valve having an axial vent therethrough, and a vent valve working in the pump cylinder in association with the vent mechanically controlled by the plunger to vent the outlet opening to the cylinder when the plunger is in retracted position and positively to close the vent when the plunger, in being moved from its retracted position, reaches an intermediate position prior to closing of the cylinder inlet, the vent valve maintaining the vent positively closed throughout the remainder of a pressure stroke and also during retraction of the plunger provided the plunger is not retracted past said intermediate position.

9. A lubricant pump comprising a lubricant container, a pump cylinder associated with the container having a radial inlet in communication with the container and an enlarged axial outlet opening at one end providing an annular outwardly facing valve seat at the inner end of the opening, a handle mounted for swinging movement toward and away from the container connected' to the plunger for manually moving it across the inlet from a retracted position through a pressure Stroke when the handle is swung away from the container, the retracted position of the plunger being determined by engagement of the handle with the container, the container being engaged by the part of the handle grasped by the hand so that in grasping the handle it is necessarily moved away from the container, and so that while the handle is grasped it cannot be moved into engagement with the'contaner, a spring biasing the check valve toward the valve seat, the check valve having an axial vent therethrough, and a Vent valve working in the pump cylinder in association with the vent mechanically controlled by the plunger to vent the outlet opening to the cylinder when the plunger is in retracted position and positively to close the vent when the plunger, in being moved from its retracted position, reaches an intermediate position prior to closing of the cylinder inlet, the vent valve maintaining the vent positively closed throughout the remainder of a pressure stroke and also during retraction of the plunger provided the plunger is not retracted past said intermediate position.

10. A lubricant pump as set forth in claim 7, further comprising a pressure indicator associated with the pump cylinder having a port in communication with the pump outlet and adapted to indicate development of a predetermined pressure by the pump.

1l. A lubricant pump as set forth in claim 8, further comprising a pressure indicator associated with the pump cylinder comprising a telltale biased in one direction to a retracted position by a spring and in the oppositedirection by pressure in the pump outlet and adapted to move away from retracted position against the spring bias when the pressure in the pump outlet reaches a predetermined value.

l2. A lubricant pump as set forth in claim 9, further comprising a pressure indicator associated with the pump cylinder comprising a stem axially movable in a chamber and spring-biased in one direction to a retracted position in the chamber, said stem being biased in the opposite direction by the pressure in the pump outlet and adapted to move away from its retracted position against its spring bias to a position protruding from the chamber when the pressure in the pump outlet exceeds a predetermined valve.

13. A lubricant pump comprising a pump cylinder havingl a radial inlet and an enlarged axial outlet opening at one end providing an annular outwardly facing valve seat at the inner end of the opening, a plunger reciprocable in the cylinder and movable across the inlet from a retracted position toward the outlet opening through a pressure stroke and back to retracted position through a return stroke, a check valve in the outlet opening, a spring biasing the check valve toward the valve seat, the check valve having an axial vent therethrough, a vent valve in the pump cylinder for closing the vent, a spring for biasing the vent valve to closed position, and means carried by the plunger cooperable with said vent valve biasing spring for relieving the vent valve of the bias of said vent valve biasing spring when the plunger is in retracted position, the vent valve otherwise being biased closed.

14. A lubricant pump comprising a pump cylinder having a radial inlet and an enlarged axial outlet opening at one end providing an annular outwardly facing valve seat at the inner end of the opening, a plunger reciprocable in the cylinder and movable across the inlet from a retracted position toward the outlet opening through a pressure stroke and back to retracted position through a return stroke, a check valve in the outlet opening, a spring biasing the check valve toward the valve seat, the check valve having an axial vent therethrough, the plunger being hollow and provided with an inwardly directed flange at its working end defining a central opening, a needle valve adapted to close the vent axially slidable in said central opening, a compression spring in the plunger reacting from a seat at the other end of the plunger against a member slidable in the plunger, said member being engaged by said flange only when the plunger is in retracted position and thereby being moved away from the end of the needle valve in the plunger to relieve the needle valve of the force of said compression spring, the needle valve being subjected to the force of said compression spring in all other positions of the plunger.

15. A lubricant pump comprising a lubricantcontaining barrel, a pump cylinder iitted in one end of the barrel extending axially of the barrel, the cylinder having a radial inlet port spaced from its inner end in communication with the interior of the barrel and having an enlarged axial outlet opening at its outer end providing an annular outwardly facing valve seat, a plunger reciprocable in the cylinder and movable across the inlet port from a retracted position toward the outlet opening through a pressure stroke, a head on the other end of the barrel, a rod slidable in the head aligned with the plunger, a plunger return spring in the barrel biasing 'the plunger into engagement with the inner end of the rod within the barrel, a handle connected to the outer end of the rod and linked to the head for swinging movement toward and away from the barrel to drive the plunger through a pressure stroke when swung away from the barrel, the retracted position of the plunger being determined by engagement of the handle with the barrel, the barrel being engaged by the part of the handle grasped by the hand, a check valve in the outlet opening, a spring biasing the check valve toward the valve seat, the check valve having an axial vent therethrough, the plunger being hollow, closed at its end engaged with the rod and having an inwardly directed flange at its other end defining a central opening, .aA needle valve adapted to close the vent extending axially in the pump cylinder and slidable in said central op-ening, a, valve stem extending from an annular shoulder at the end of the needle valve in the plunger, a collar slidable on the valve stem, a compression spring in the plunger reacting from the closed end of the plunger against the collar, the arrangement being such that when the plunger is in retracted position, the ange at the lower end of the plunger engages the collar and holds it away from the shoulder to relieve the vent valve of the force of the spring in the plunger, the needle valve being subjected to spring force in all other positions of the plunger.

16. A lubricant pump comprising a pump cylinder having a radial inlet and an enlarged axial outlet opening at one end providing an annular outwardly facing valve seat at the inner end of the opening, a plunger reciprocable in the cylinder and movable across the inlet from a retracted position toward the outlet opening through a pressure stroke and back to retracted position through a return stroke, a check valve in the outlet opening, a spring biasing the check valve toward the valve seat, the check valve having an axial vent therethrough, and a vent valve extending from the plunger comprising a rod sized for a sliding sealing t in the vent, said rod being of such length that when the plunger is in retracted position, the rod is withdrawn from the vent, and in all other positions of the plunger is entered in and seals the vent.

17. A lubricant pump comprising a pump cylinder having a radial inlet and an enlarged axial outlet opening at one end providing an annular outwardly facing valve seat at the inner end of the opening, a plunger reciprocable in the cylinder and movable across the inlet from a retracted position toward the outlet opening through a pressure stroke and back to retracted position through a return stroke, a check valve in the outlet opening, a spring biasing the check valve toward the valve seat, the check valve having an axial vent therethrough, said check valve comprising a hollow cylindrical body formed at one end with a nose for sealing engagement with the valve seat and open at its other end, and having an axial Vent opening through the nose, an annular packing in the body compressed against the nose by a gland fitted in the'open end of the body, the openings in the nose and packing dening a vent, and a vent valve extending from the plunger comprising a rod sized for a sliding sealing t in the vent, said rod being of such length that when the plunger is in retracted position, the rod is withdrawn from the vent, and in all other positions of the plunger is entered in and seals the vent.

18. A lubricant pump comprising a container, a head at one end of the container containing a pump cylinder extending transverse to the container, the cylinder having a radial inlet port in communication with the container through a passage in the head, the cylinder having an enlarged axial outlet opening in one end providing an annular outwardly facing valve seat, the head having a pump outlet port in communication with the outlet opening of the cylinder, a plunger reciprocable in the cylinder and movable across the inlet port from a retracted position toward the outlet opening through a pressure stroke, a handle connected to the plunger and linked to the head for swinging movement toward and away from the container to drive the plunger through a pressure stroke when swung away from the container, the retracted position of the plunger being determined by engagement of the handle with the container, the container being engaged by the part of the handle grasped by the hand, a check valve in the outlet opening, a spring biasing the check valve toward the valve seat, the check valve having an axial vent therethrough, and a vent valve extending from the plunger comprising a rod sized for a sliding sealing t in the vent, the rod being of such length that when the plunger is in retracted position, the rod is withdrawn 16 from the vent, and in all other positions of the plunger is entered in and seals the vent.

19. A lubricant pump for injectors, comprising a pump cylinder having an inlet and an outlet, a plunger reciprocable in the cylinder from a retracted position through a pressure stroke and back to retracted position through a return stroke, the cylinder inlet being open when the plunger is in retracted position and closing upon movement of the plunger from retracted position, a check valve in the cylinder outlet opening upon pressure strokes and closing upon return strokes, a vent passage by-passing the check Valve, a vent valve mechanically associated with and controlled by the plunger for opening and closing the vent passage upon movement of the plunger, the mechanical correlation between the plunger and the vent valve being such that the vent passage is opened only when the plunger is in a retracted position, the cylinder inlet being opened during return strokes of the plunger before it reaches its retracted position, and means for operating the plunger through pressure and return strokes without full return of the plunger to retracted position.

20. A lubricant pump as set forth in claim 19 wherein the operating means for the plunger comprises a handle for manually operating the plunger through pressure and return strokes, the pump further including stop means adapted when the handle is grasped to prevent return of the plunger to its retracted position, and means biasing the plunger to its retracted position when the handle is released.

ALEXANDER P, FOX. LUTWIN C. ROTTER.

REFERENCES CITED The following references are of record in the ile of this patent:

UNITED STATES PATENTS Number Name Date 1,761,127 Jacques June 3, 1930 1,909,348 Hallerberg May 16, 1933 1,915,443 Pelouch June 27, 1933 1,947,088 Johnson Feb. 13, 1934 

